Vertically movable self-locking shutter

ABSTRACT

An exposed shutter having horizontally disposed slats movable between a raised, stacked condition and a lowered, spaced condition; the slats being provided with end fittings slidable on fixed vertical guides and linkage arranged to tilt and lock each slat in a predetermined angular position as it reaches its spaced condition, and further includes a final locking mechanism operable, when the shutter is extended, to secure all the slats so as to resist windloads; the shutter being raised and lowered by tapes which also function to release the locking mechanism.

United States Patent 1,965,262 7/ 1 934 Seregi 160/165X 2,242,697 5/ l941 Duca 160/172 2,551,736 5/1951 Guarcello... 160/172X 2,639,766 5/1953Pratt l60/l72X 3,473,597 10/ 1969 Chevaux 160/165X PrimaryExaminer-Peter M. Caun ABSTRACT: An exposed shutter having horizontallydisposed slats movable between a raised, stacked condition and alowered, spaced condition; the slats being provided with end fittingsslidable on fixed vertical guides and linkage arranged to tilt and lockeach slat in a predetermined angular position as it reaches its spacedcondition, and further includes a final locking mechanism operable, whenthe shutter is extended, to secure all the slats so as to resistwindloads; the shutter being raised and lowered by tapes which alsofunction to release the locking mechanism.

PATENTED MAY] 1' I971 SHEET 2 OF 2 INVENTOR.

VERTICALLY MOVABLE SELF-LOCKINGSIIU'ITER BACKGROUND OF THE INVENTIONOutside or exposed shutters are of the vertical slat-type or horizontalslat-type. Because of windload problems, it: has

LII

been necessary to fix the slats in position; however, in some in stancesthe slats have been mounted for rotationabout'their longitudinal axes.In either case, however, the shutters are permanently mounted in frontof the window; whereas, it would be desirable to remove the shuttersfrom in front of the window when they are not needed or iniorder toclean the window. Also, if the slats are individually rotated, themechanism is complicated, and often produces noise when the shutters aresubject to wind.

SUMMARY OF THE INVENTION links in such a manner that each slat causesthe preceding slat to be locked in position as the slats are lowered,and which incorporates means for locking the lowermost slat'when theshutter is fully extended.

Third, to provide in a vertically movable shutter a simple motoroperated means to effect raising and'lowering-the shutter, utilizingthin tapes which are wrapped on drums mounted on a common drive shaftwhich also carriesa novel spiral member for moving a limit switchengaging traveler.

Fourth, to provide a vertically movable shutter which may be prearrangedwith minimal change in parts .to dispose the slats, when extended, inessentially horizontal position as forsouthern exposure or in an angularposition as for east or west exposure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary end view of thevertically movable self-locking shutter, shown in its extended conditionwith" the housing shown fragmentarily.

FIG. 2 is an end view of the shutter in its raised condition, with thehousing indicated in section.

FIG. 3 is an enlarged fragmentary longitudinal sectional view, takenthrough 3-3 of FIG. 1.

FIG. 4 is another fragmentary longitudinal sectional view, taken through4-4 of FIG. 3.

FIG. 5 is a further enlarged transverse sectional view, taken through5-5 of FIG. 4.

FIG. 6 is another further enlarged transverse sectional view, takenthrough 6-6 of FIG. 4.

FIG. 7 is a fragmentary end view of the shutter, illustrating the mannerin which each slat .moves between its stacked and.

its extended and locked position.

FIG. 8 is a sectional view of an end fitting, taken within circle 8 ofFIG. 7, showing an adjacent portion 'of the guide member in elevation toillustrate the clearance between the. end fitting and the guide memberwhen the end'fitting is:in its stacked position.

FIG. 9 is a fragmentary sectional view, similar to FIG. 8; taken withincircle 9 of FIG. 7, and showing'an end fitting in locking engagementwith the guide memben FIG. 10 is a fragmentarytplan view of the shutterwith the housingremoved.

FIG. 11 is an enlarged fragmentary sectional view, taken from 11-11 ofFIG. 10, showing the traveler and the screw coil.

FIG. 12 is a fragmentary sectional view thereof, taken through 12-12ofFlG. I1.

FIG. 13 is an enlarged fragmentary sectional view, taken through 13-13of FIG. .1, showing one ofthe'slats in plan and showing by broken linesa means whereby slats may be connected horizontally.

FIG. 14 is an enlarged fragmentary side view, taken from l4-I4'of FIG.1, and showing a single slat.

FIG. 15'is a fragmentary end view, similar to FIG. 7, but illustratingthe manner in which the slats, end fittings, and linkage may berearranged to place the slats in essentially horizontal positions whenextended.

FIG. 16 is a fragmentary sectional view, taken within circle 16 of FIG.15, and corresponding to FIG. 8' to illustrate the free'sliding relationbetween a fitting, when stacked, and the guide member.

FIG. 17 is a corresponding sectional view, taken within circle l7of-FIG. 15, illustrating an end fitting in its locked position on theguide member.

FIG. 18 is an end view of a modified end fitting and a modified slat.secured thereto.

FIG; 19 is a fragmentary sectional view thereof, taken through 19-19 ofFIG. 18.

FIG. 20-is a fragmentary sectional view, taken through 20-20 of FIG. 13,illustrating the clampingmeans for joining slats end-to-end.

Thevertically movable self-locking shutter includes a set of slats 1,which may be formed of various materials such as fiber glass, aluminumextrusions, or folded sheet'metal. The transverse profile of the slatsmay for ornamental purposes take various forms; it is essential,however, that the slats be selfsupporting when held merely at theirends. By wayof example, each slat may include a central web 2, borderedby inner flanges 3, extending in opposite directions therefrom andjoined to lateral webs 4 having marginal flanges 5 also extending'inopposite directions.

Each slat is provided with a pair of end fittings 6, which may be in theform of metal castings such as aluminum die castings or injection moldedof high strength plastic. Each end fitting.

includes a cross plate 7'which underlies the end of a slat 1', overwhichis placed a clampplate 8 secured to the cross plates by screws or rivets9. A pair of parallel arms-l0'extend from the plate 7. The confrontingsides of the arms'10 are provided with beveled binding faces 11 andangularly related clearance end faces 12. The arms terminate incylindrical end portions 13. The. end fittingsare arrangedin right andleft pairs; however, if the arms are cylindrical, the same end fittingmay be mounted at either end of the slat 1.

Each shutter utilizes a pair of fixed guide members 14, preferablychannel shaped in cross section and thus include webs 15 joined toparallel side flanges 16 having inturned extremities 17. Each guidemember is also provided at the side margins of its web 15' with internalguide ribs 18, forming therebetween a shallow clearance channel. Eachguide member is supported from a wall or window frame by an upperbracket 19 and a lower bracket 20. The upper brackets serve to support ahousing 21, having a sloping upper wall and a depending outer wall. Thearms 10 of each fitting extend across the side flanges and are spaced sothat the end fittings 6 and the slats supported have limited angularmovement.

One. arm of eachend fitting 6 receives a pivot 22, which may be a rivetor screw, and journals a minor link 23 in the form of a metal strip. Theextremity of each link is folded to form a stop 24 which engages a sideflange 16 of a corresponding guide member 14. The other arm of eachfitting 6 receives a pivot '25, similar to the pivot 22, which journalsa major link 26. The minor link 23 of the preceding fitting 6 is joinedto the major link 26 of the succeeding fitting by a'pivot 27, the majorposed clearance recesses 30' to receive guide wheels 3I mounted onshafts32 pressfitted in the weight bar. The wheels ride loosely between theside flanges 16 and are loosely retained between the inturned portions17 and ribs 18. The bottom end of the weight bar forms a depending yoke33 forming a slot with parallel walls, having an opposed pair of slopingcam or wedge slots 34. Received in the yoke is a latch bolt 35 ofrectangular cross section. The latch bolt is provided with a pair ofmounting screws 36, provided with rollers 37 adapted to ride in thewedge slots 34 to move the latch bolt 35 to and from a confronting sideflange 16. Secured to the latch bolt is a latch strip 38, having,preferably, fine teeth 39 which mate with corresponding teeth 40provided in a keeper strip 41 secured to the confronting side flange 16.

Secured to the latch bolt 35 by the screws 36 is a stacking cage 42which includes a crossmember 43 disposed across the open side of theguide member and receiving the screws, and an upright angle member 44.One flange of the upright member confronts the guide member 14 and formsa lateral stop 45 for the cylindrical end portion 13 of the arm 10 whichreceives the pivot 25 to which the major link 26 is connected. The upperedge of the crossmember 43 at the bottom of the lateral stop 45 forms abottom stop 46. The crossmember 43 is provided with a lateral projection430 which is connected to the lowermost end fitting by a modified link23a.

The two weight bars 29 are suspended and moved by tapes 47; preferablymetal tapes such as used for flexible measuring tapes. Such tapes havehigh tensional strength capable of supporting the loads imposed andcapable of being wrapped about a drum 48 of small diameter. Also, suchtapes are quite thin so that change in diameter as the wrapped tape evenfor a shutter 8 feet or so in height is minimal. The upper end of eachweight bar is provided with a cross bore 49 intersected by a slit 50.The cross bore and slit receives the looped end of a tape 47. The tapeis secured by an expansion plug 51 of a suitable elastomer. A bolt 52,having a washer 53 and nut disc 54 is employed to squeeze the plug 51axially so as to lock the tape in place.-

The pair of tape drums 48 are mounted above the guide members. One drumis joined to a control shaft 55 and the other to an extension shaft 56,coaxially connected by a coupling 57. The shafts are suitably journaledin upper mounting brackets 19. The control shaft, which may be of afixed length irrespective of the width of the shutter, is mountedbetween a pair of such brackets and its extremity is provided with agear 58. A motor 59, suitably supported from a bracket 19 is providedwith a pinion gear which engages the gear 58. The motor, which isconventional, is reversible and preferably provided with a lock toprevent rotation when not in operation.

Mounted on the control shaft 55 is a lead screw 61. The lead screw maybe a helically coiled wire or tube secured at its extremities to theshaft as the axial thrust imposed is minimal. A pair of guide rods 62,parallel to the shaft, receive a traveler bar 63 which journals a pin64, having a grooved head fitting the lead screw and functioning as ahalf nut. The traveler bar 63 is provided with setscrews 65 which engagelimit switches 66 mounted on bars 67 also supported and axiallyadjustable on the guide rods 62. The limit switches serve to stopmovement of the shutter at its stacked condition and at its extendedcondition by conventional electrical connection with the motor 59.

Operation of the vertically movable self-locking shutter is as follows:

When the slats are stacked, the slats 1 are in an essentially horizontalposition, the end fittings 6 are tilted so that the arms 10 clear theguide members 14, as shown in FIG. 8. The stacking cage 42, lateral stop45 and bottom stop 46, in conjunction with the lowermost minor link 23,hold the lowermost end fitting at the correct angle. The other endfittings stack thereon and are restrained by the lateral stop 45.

When the motor turns the drums to unwind the tapes, the stacked slatsmove downward by gravity. The uppermost slat lifts from the stack andpivots from the horizontal position shown in FIG. 2 to the inclinedposition shown in FIG. 1. As illustrated, particularly in FIG. 7 and bycomparison of FIGS. 8 and 9, the end fittings reverse their angle ofinclination, for example, between an angle of 20 in one direction to anangle of 30 in the opposite direction.

At the latter angle, the faces 11 of the arms 10 tend to bind againstthe guide member 14, each major link 26- pulls upwardly on the endfitting while the minor link 23 pulls downwardly, securely locking theend fitting and the corresponding slat. As the slats progressively liftfrom the stack, or more correctly, the stack moves downwardly, the endfittings and the slat therebetween are progressively locked in position.The links 23 and 26 are prevented from aligning by the stop tabs 24which engage the guide member.

When the bottom or final slat has tilted, as indicated in FIG. 1, theweight bars continue to move downwardly, causing the latch bolt to movelaterally until the latch and keeper teeth 39 and 40 interlock, securingthe lowermost slat, and, indirectly, securing all of the slats above.

The limit switch controlling downward movement of the shutter ispreferably adjusted to permit limited overtravel so that the weight barsmaintain a load on the latch bolts.

When the motor 59 is operated to turn the drums 48 in a direction toraise the tapes 47, the weight bars 21 are first raised to disengage thelatch bolts 35. Further upward movement tilts the end fittings 6 andcorresponding slats 1 in sequence from the tilted position shown in FIG.1 and top of FIG. 7 to the stacked position shown in FIG. 2 and bottomof FIG. 7. This progressive action continues until the slats arecompletely stacked as indicated in FIG. 2. The uppermost pair of links23 and 26 are not completely folded to pennit some tolerance in theoperation of the limit switch which stops upward movement.

Tests have indicated that slats having a plan width of 8 inches may havean extended spacing of 6 inches and a stacked spacing of one-half inch,so that the shutter occupies a minimum of space when stacked.

The arrangement shown in FIGS. 1 through 14 is such that, when tilted,the lower edge of the upper slat is level or nearly so, with the upperedge of the lower slat and thus, is particularly suited for East andWest exposure. For Southern exposure, and to minimize view obstruction,it is sometimes desirable that the slats be horizontal or only slightlytilted when extended.

If the slat 1 is inverted as shown in FIG. 15, and the end fitting bemoved only slightly from their binding position; that is, between thepositions shown in FIG. 16 and FIG. 17, this result can be attained. insuch case, it is desirable to reverse the positions of the major link 26and minor link 23 and to substitute a modified stacking cage 68, havinga crossmember 69 fastened similarly to the crossmember 43 to the latchbolt 35. The vertical angle member 70 is provided with a lateral stop 71and a slot 72 at the lower end of the angle member to receive a pivot22a extending from the lowermost end fitting. This fitting is held atthe proper angle by an extension 73, corresponding to the extension 43aand link 23a.

Operation of the modified shutter is essentially the same as the firstdescribed construction, the essential difference being that the angularmovement of the slats is minimal.

Reference is now directed to FIGS. 18 and 19 which illustrate a modifiedend fitting 74 having arms 10 as in the first described structure, buthaving a cross plate 75 which is twisted with respect to the commonplane of the two arms 10 and joined by transition portions 76dimensioned so that the modified fitting stacks in the samecenter-to-center spacing as the fitting 6. This arrangement permits theuse of a a modified slat 77 which may be channel shaped, comprising aweb 78 and depending side flanges 79, and may be substituted for theinverted slat 1 for Southern exposure.

In this regard, it should be noted that the slat clamping plane of theend fitting may be varied to accommodate slats of various transverseprofile.

If it is desired to provide a shutter to cover a row of windows, themarginal flanges 5 and adjacent portions of the lateral webs 4 may beprovided at their extremities with clamp members 80 which are joined tothe slats of the adjacent shutter, as indicated by broken lines in FIG.13. With this arrangement, one guide post 14, and: one set of endfittings and links may serve for the adjacent shutters. In this case,the drums 48 for the shutters may be mounted on a single shaft,individual motor drives may be retained; however, only. one set of limitswitches is required.

While particular embodiments of this invention have been shown anddescribed, it is not intended to limit the same to the details of theconstructions set forth, but instead, the invention embracessuchchanges, modifications and equivalents of the various parts and theirrelationships as come within the purview of the appended claims.

lclaim: l. A shutter construction, comprising: a. a pair of verticalguide posts; b. a plurality of slats extending horizontallytherebetween; c. fittings for said slats tiltable between a slidableposition and a locking position relative to said'posts; v

d. linkage serially connecting said fittings, said linkage operable topen'nit said fittings to occupy a slidable position relative to saidposts, and operable, when extended, to tilt said fittings to a lockedposition relative to said posts;

e. an extensible and retractable operating mechanism for connection withthe fittings of the lowermost slat, causing said linkage and slats to beextended in sequence and for causing said linkage and slats to stack insequence;

. the fittings of each slat, on'becoming locked, being operable throughtheir corresponding linkage to secure the fittings of the preceding slatagainst displacement from their locked position;

g. and latching means actuated by the operating means, as the operatingmeans approaches its extendedposition and as the fittings of thelowermost slat approach their locking position, to secure said fittingsagainst displacement from their locked position by force applied to thelowermost slat independent of the operating mechanism;

means on initialretraction thereof to free the lowermost fittings andpermit stacking of the linkage and slats. 2. A shutter, as defined inclaim 1, wherein:

a. each fitting is disposed at an end of its slat and extends acrossthree sides of a post;

b. and each linkage extends across the fourth side of said post betweenadjacent end fittings.

3. A shutter, as defined in claim l, wherein:

a. said operating mechanism includes means operable on predetenninedretraction thereof for disposing the lowermost fittings and theircorresponding slat in a predetermined slidable position on said posts,and means for aligning the remaining fittings and their slats in acorresponding slidable position and in stacked relation thereon.

4. A shutter, as defined in claim 2, wherein:

a. said posts are hollow to form guideways;

b. said operating mechanism includes suspension means movable in saidguideways and connected withthe lowermost end fittings to permitextension of said end fittings and slats by gravity.

5. A shutter, as defined in claim 4, wherein:

a. said operating mechanism and locking means further includes weightmembers and latch elements carried thereby interposed between saidsuspension means and said lowermost end fittings; said latch elementsbeing movable by said weight members into locking engagement with saidposts to secure said lowermost end fittings against displacement uponterminating extension movement of said lowermost end fittings, saidlatchelements being movable to free said lowermost cnd' fittings upon raisingsaid suspension means and saidweight members.

6v Ashuttcr, as defined in claim I, wherein:

a. said posts are hollow to form guideways;

. said latching means also being activated by the operating.

said operating mechanism includes flexible metal suspension tapesmovable in said guideways and connected to the lowermost fittings topermit extension of said fittings and slats by, gravity, drums receivingsaid tapes, a shaft therefor, and a motor for turning said shaft anddrums in a selected direction.

7. A shutter, as defined in claim 6, wherein:

a. said operating mechanism further includes a helical coil wrappedabout said shaft to form a lead screw, a traveler movable along saidlead screw coil and spaced limit switches for controlling said motor andengaged by said traveler.

8. A shutter construction, comprising:

a. a pair of fixed guide posts adapted to be mounted vertically atopposite sides of a window and spaced outwardly therefrom;

b. two sets of end fittings guided by said posts and tiltable between alocking position and a sliding position thereon, each of said fittingsincluding a cross portion and first and second arms engageable withopposite sides of the corresponding post to bind said fitting againstsliding movement thereon, and movable to clear said sides thereby topermit sliding movement of said fitting thereon;

c. a set of slats extending between said posts and secured to the crossportions of opposing pairs of said fittings, said slats being movablebetween a spaced operating position when said fittings occupy theirlocked position, and a contiguous stacked position when said fittingsoccupy their sliding position;

d. a set of linkages, each linkage being attached to a first arm of onefitting and to the second arm of the next fitting thereby connecting themembers of each set of fittings in series whereby, on tensioning saidlinkage, said slats are spaced and said fittings are locked with respectto said posts;

e. and means for effecting movement of said slats between their spacedoperating position and their stacked position.

9. A shutter construction, as defined in claim 8, wherein:

a. said posts are channel shaped;

b. and said movement effecting means includes tension members extendinglongitudinally within said' channels and connected to the lowermost pairof end fittings, said tension members being operable to permit loweringand spacing of said end fittings until said end fittings lock on saidguide posts, and operable to raise said fittings and slats to theirstacked position.

10. A-shutter construction, as defined in claim 8, wherein:

a. said posts are channel shaped;

b; and said movement efi'ecting means includes a weight member movablein each of said posts and connected with acorresponding lowermost endfitting, and'a longitudinally movable tension member suspending saidweight members; said weight members when permitted by said tensionmembers, tending to move said end fittings and slats to their extended,locked position, said tension members operable to raise said endfittings and slats to their stacked position.

11. A shutter construction, as defined in claim 10, which furthercomprises:

a. a latchmeans including a bolt member carried by each weight memberand connected to a lowermost end'fitting, a keeper fixed in the lowerend of each guide post, and

means operable as said weight members reach their lowermost position tocause mutual engagement of said bolt and keeper to lock said endfittings against upward displacement, said means being releaseable uponraising said weight members.

12. A shutter construction, as defined in claim 8, wherein:

a. said slats, when in their stacked, as well as their operatingposition, are essentially horizontal;

h.- and said end fittings tilt a-minimal distance from their lockedpositions to their slidable positions.

[3. A shutter construction, as defined in claim 8, wherein:

a. said slats, when in their stacked position, are disposed essentiallyhorizontal, and when in their operating position are tilted to place thelower edge of an upper slat in an essentially horizontal common planewith the upper edge of the next slat below;

b. and said end fittings pivot from an angular locking position througha horizontal position to an oppositely sloping, sliding position.

14. A shutter construction, comprising:

a. a pair of guide posts of channel cross section;

b. a set of horizontally disposed individually tiltable slats extendingbetween the posts;

c. means serially connecting the slats for vertical and tilting movementof each slat between a stacked position and an extended position, saidslats and connecting means therebetween engageable with the posts tocause each slat to bind against vertical movement when in its extendedposition;

d. operating means vertically movable in the posts and attached to thelowermost slat to cause sequential movement of the slats to theirrespective binding positions as the operating means is lowered and tocause sequential movement of the slats toward their respective stackedpositions as the operating means is raised;

e. and locking means responsive to the operating means, as it approachesits lowermost position, to secure the lower most slat in its bindingposition thereby to secure the other slats above in their respectivebinding positions, and responsive to the operating means as theoperating means retreats from its lowermost position to release thelowermost slat for movement toward its stacked position and permits, asthe operating means is raised, the slats above to assume their stackedpositions.

15. A shutter, as defined in claim 14, wherein said operating mechanismcomprises:

a. a flexible metal tape in each guide post;

b. a drum on which each tape is spirally wrapped, the convolutions beingin a common plane;

c. a shaft connecting the drums;

d. and a motor for turning the shaft and drums in a selected direction.

16. A shutter, as defined in claim 15, wherein the operating mechanismfurther comprises:

a. a helical coil wrapped about the shaft to form a lead screw;

b. a traveler member movable along the lead screw;

0. and spaced limit switches for controlling the motor engaged by thetraveler.

17. An operating mechanism for shutters having a set of verticallymovable and tiltable slats positioned between a pair of vertical guideposts having guide channels therein, the lowermost slat having means forattachment to the operating mechanism, said operating mechanismcomprising:

a. a pair of flexible metal tapes joined at their lower ends to saidattachment means and extending upwardly therefrom through the guidechannels;

b. a pair of similar drums at the upper ends of the guide posts on whichthe tapes are spirally wrapped, the convolutions of each tape occupyinga common plane, the tapes being equal in length and thickness as well assimilarly wrapped on their drums whereby the tapes advance and retractequally thereby to effect equal movement of both ends of the slats;

c. a drive shaft extending between the drums for turning the drums inunison;

d, and means for turning the shaft.

18. An operating means, as defined in claim 17, which further comprises:

a7 a relatively stiff helical coil secured to the drive shaft;

b. a parallel shaft;

c. a traveler member slidable on the parallel shaft and engageable withthe convolutions of the coil for movement along the drive shaft;

d. a pair of spaced limit switches positioned for engagement by thetraveler member; e. and the shaft turning means the limit switches.

being a motor controlled by

1. A shutter construction, comprising: a. a pair of vertical guideposts; b. a plurality of slats extending horizontally therebetween; c.fittings for said slats tiltable between a slidable position and alocking position relative to said posts; d. linkage serially connectingsaid fittings, said linkage operable to permit said fittings to occupy aslidable position relative to said posts, and operable, when extended,to tilt said fittings to a locked position relative to said posts; e. anextensible and retractable operating mechanism for connection with thefittings of the lowermost slat, causing said linkage and slats to beextended in sequence and for causing said linkage and slats to stack insequence; f. the fittings of each slat, on becoming locked, beingoperable through their corresponding linkage to secure the fittings ofthe preceding slat against displacement from their locked position; g.and latching means actuated by the operating means, as the operatingmeans approaches its extended position and as the fittings of thelowermost slat approach their locking position, to secure said fittingsagainst displacement from their locked position by force applied to thelowermost slat independent of the operating mechanism; h. said latchingmeans also being activated by the operating means on initial retractionthereof to free the lowermost fittings and permit stacking of thelinkage and slats.
 2. A shutter, as defined in claim 1, wherein: a. eachfitting is disposed at an end of its slat and extends across three sidesof a post; b. and each linkage extends across the fourth side of saidpost between adjacent end fittings.
 3. A shutter, as defined in claim 1,wherein: a. said operating mechanism includes means operable onpredetermined retraction thereof for disposing the lowermost fittingsand their corresponding slat in a predetermined slidable position onsaid posts, and means for aLigning the remaining fittings and theirslats in a corresponding slidable position and in stacked relationthereon.
 4. A shutter, as defined in claim 2, wherein: a. said posts arehollow to form guideways; b. said operating mechanism includessuspension means movable in said guideways and connected with thelowermost end fittings to permit extension of said end fittings andslats by gravity.
 5. A shutter, as defined in claim 4, wherein: a. saidoperating mechanism and locking means further includes weight membersand latch elements carried thereby interposed between said suspensionmeans and said lowermost end fittings; said latch elements being movableby said weight members into locking engagement with said posts to securesaid lowermost end fittings against displacement upon terminatingextension movement of said lowermost end fittings, said latch elementsbeing movable to free said lowermost end fittings upon raising saidsuspension means and said weight members.
 6. A shutter, as defined inclaim 1, wherein: a. said posts are hollow to form guideways; b. saidoperating mechanism includes flexible metal suspension tapes movable insaid guideways and connected to the lowermost fittings to permitextension of said fittings and slats by gravity, drums receiving saidtapes, a shaft therefor, and a motor for turning said shaft and drums ina selected direction.
 7. A shutter, as defined in claim 6, wherein: a.said operating mechanism further includes a helical coil wrapped aboutsaid shaft to form a lead screw, a traveler movable along said leadscrew coil and spaced limit switches for controlling said motor andengaged by said traveler.
 8. A shutter construction, comprising: a. apair of fixed guide posts adapted to be mounted vertically at oppositesides of a window and spaced outwardly therefrom; b. two sets of endfittings guided by said posts and tiltable between a locking positionand a sliding position thereon, each of said fittings including a crossportion and first and second arms engageable with opposite sides of thecorresponding post to bind said fitting against sliding movementthereon, and movable to clear said sides thereby to permit slidingmovement of said fitting thereon; c. a set of slats extending betweensaid posts and secured to the cross portions of opposing pairs of saidfittings, said slats being movable between a spaced operating positionwhen said fittings occupy their locked position, and a contiguousstacked position when said fittings occupy their sliding position; d. aset of linkages, each linkage being attached to a first arm of onefitting and to the second arm of the next fitting thereby connecting themembers of each set of fittings in series whereby, on tensioning saidlinkage, said slats are spaced and said fittings are locked with respectto said posts; e. and means for effecting movement of said slats betweentheir spaced operating position and their stacked position.
 9. A shutterconstruction, as defined in claim 8, wherein: a. said posts are channelshaped; b. and said movement effecting means includes tension membersextending longitudinally within said channels and connected to thelowermost pair of end fittings, said tension members being operable topermit lowering and spacing of said end fittings until said end fittingslock on said guide posts, and operable to raise said fittings and slatsto their stacked position.
 10. A shutter construction, as defined inclaim 8, wherein: a. said posts are channel shaped; b. and said movementeffecting means includes a weight member movable in each of said postsand connected with a corresponding lowermost end fitting, and alongitudinally movable tension member suspending said weight members;said weight members when permitted by said tension members, tending tomove said end fittings and slats to their extended, locked position,said tension members operable to raise said end fittings and slats totheir stacked position.
 11. A shutter construction, as defined in claim10, which further comprises: a. a latch means including a bolt membercarried by each weight member and connected to a lowermost end fitting,a keeper fixed in the lower end of each guide post, and means operableas said weight members reach their lowermost position to cause mutualengagement of said bolt and keeper to lock said end fittings againstupward displacement, said means being releaseable upon raising saidweight members.
 12. A shutter construction, as defined in claim 8,wherein: a. said slats, when in their stacked, as well as theiroperating position, are essentially horizontal; b. and said end fittingstilt a minimal distance from their locked positions to their slidablepositions.
 13. A shutter construction, as defined in claim 8, wherein:a. said slats, when in their stacked position, are disposed essentiallyhorizontal, and when in their operating position are tilted to place thelower edge of an upper slat in an essentially horizontal common planewith the upper edge of the next slat below; b. and said end fittingspivot from an angular locking position through a horizontal position toan oppositely sloping, sliding position.
 14. A shutter construction,comprising: a. a pair of guide posts of channel cross section; b. a setof horizontally disposed individually tiltable slats extending betweenthe posts; c. means serially connecting the slats for vertical andtilting movement of each slat between a stacked position and an extendedposition, said slats and connecting means therebetween engageable withthe posts to cause each slat to bind against vertical movement when inits extended position; d. operating means vertically movable in theposts and attached to the lowermost slat to cause sequential movement ofthe slats to their respective binding positions as the operating meansis lowered and to cause sequential movement of the slats toward theirrespective stacked positions as the operating means is raised; e. andlocking means responsive to the operating means, as it approaches itslowermost position, to secure the lowermost slat in its binding positionthereby to secure the other slats above in their respective bindingpositions, and responsive to the operating means as the operating meansretreats from its lowermost position to release the lowermost slat formovement toward its stacked position and permits, as the operating meansis raised, the slats above to assume their stacked positions.
 15. Ashutter, as defined in claim 14, wherein said operating mechanismcomprises: a. a flexible metal tape in each guide post; b. a drum onwhich each tape is spirally wrapped, the convolutions being in a commonplane; c. a shaft connecting the drums; d. and a motor for turning theshaft and drums in a selected direction.
 16. A shutter, as defined inclaim 15, wherein the operating mechanism further comprises: a. ahelical coil wrapped about the shaft to form a lead screw; b. a travelermember movable along the lead screw; c. and spaced limit switches forcontrolling the motor engaged by the traveler.
 17. An operatingmechanism for shutters having a set of vertically movable and tiltableslats positioned between a pair of vertical guide posts having guidechannels therein, the lowermost slat having means for attachment to theoperating mechanism, said operating mechanism comprising: a. a pair offlexible metal tapes joined at their lower ends to said attachment meansand extending upwardly therefrom through the guide channels; b. a pairof similar drums at the upper ends of the guide posts on which the tapesare spirally wrapped, the convolutions of each tape occupying a commonplane, the tapes being equal in length and thickness as well assimilarly wrapped on their drums whereby the tapes advance and retractequally thereby to effect equal movement of both ends oF the slats; c. adrive shaft extending between the drums for turning the drums in unison;d. and means for turning the shaft.
 18. An operating means, as definedin claim 17, which further comprises: a. a relatively stiff helical coilsecured to the drive shaft; b. a parallel shaft; c. a traveler memberslidable on the parallel shaft and engageable with the convolutions ofthe coil for movement along the drive shaft; d. a pair of spaced limitswitches positioned for engagement by the traveler member; e. and theshaft turning means being a motor controlled by the limit switches.